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Date: Thu, 3 Mar 2011 13:37:37 +0200 (EET)
From: Aaro Koskinen <aaro.koskinen@nokia.com>
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To: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
cc: Aaro Koskinen <aaro.koskinen@nokia.com>, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org, akpm@linux-foundation.org,
        stable@kernel.org
Subject: Re: [PATCH] procfs: fix /proc/<pid>/maps heap check
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Hi,

On Thu, 3 Mar 2011, KOSAKI Motohiro wrote:
>> On Tue, 1 Mar 2011, Aaro Koskinen wrote:
>>> The current check looks wrong and prints "[heap]" only if the mapping
>>> matches exactly the heap. However, the heap may be merged with some
>>> other mappings, and there may be also be multiple mappings.
>>>
>>> Signed-off-by: Aaro Koskinen <aaro.koskinen@nokia.com>
>>> Cc: stable@kernel.org

[...]

> Your description said,
> 	the heap may be merged with some other mappings,
>                        ^^^^^^
> but your example is splitting case. not merge. In other words, your
> patch care splitting case but break merge case.
>
> Ok, we have no obvious correct behavior. This is debatable. So,
> Why do you think vma splitting case is important than merge?

Sorry, I was unclear.

The current behaviour is wrong for both merged and split cases, and I
think the patch fixes both.

And yes, the example program is for the split case. I'll see if I can
make a test program for the merged case...

A.
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